The invention concerns a device for transporting printed sheets, in particular in a gathering and stitching machine or an assembling machine having a traction element to which there is connected a saddle-shaped support or an approximately level support on which the printed sheets are successively deposited in adjacent stacks, either straddling the saddle-shaped support or forming a piles of sheets on the level support, and particularly to such a device having a mechanism for holding down the deposited printed sheets.
Gathering and stitching, as well as assembling machines, are well known. European application EP-A-0 681 923, for example, shows a gathering and stitching machine with a device of the generic type, wherein a traction element is provided with a saddle-shaped support which transports the printed sheets that are successively deposited thereon in a straddling manner by distributors. In assembling machines the support is level and moves in a horizontal conveying direction. The traction element in this case can be an endlessly circulating belt. In order to increase the capacity of gathering and stitching machines and assembling machines, it has long been a desire to transport the printed sheets in the aforementioned device at higher speeds than has been possible so far. The difficulty here is that, in particular, thin and light weight printed sheets will lift off, fly away or the edges will be folded over, which leads to interruptions in the continued processing of the printed sheets. It is a known practice to exert control over the printed sheets during the transport by aiming a blast of air at them, weighing them down with brake springs or holding them down, for example with brushes. However, blast air is hard to control and can have disadvantageous effects in addition to being expensive. Hold-down devices have the essential disadvantage that access to the printed sheets is limited during transport and the known hold-down devices in each case must be adjusted exactly to the respective products.